From: Anup Patel <apatel@ventanamicro.com>
Date: Mon, 9 May 2022 05:13:46 +0000 (+0530)
Subject: RISC-V: KVM: Treat SBI HFENCE calls as NOPs
X-Git-Tag: howlett/maple/20220722_2~444^2~11^2~6
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=c7fa3c48de86053b0f1949fa5532082544e30fce;p=users%2Fjedix%2Flinux-maple.git

RISC-V: KVM: Treat SBI HFENCE calls as NOPs

We should treat SBI HFENCE calls as NOPs until nested virtualization
is supported by KVM RISC-V. This will help us test booting a hypervisor
under KVM RISC-V.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
---

diff --git a/arch/riscv/kvm/vcpu_sbi_replace.c b/arch/riscv/kvm/vcpu_sbi_replace.c
index 0f217365c287..3c1dcd38358e 100644
--- a/arch/riscv/kvm/vcpu_sbi_replace.c
+++ b/arch/riscv/kvm/vcpu_sbi_replace.c
@@ -117,7 +117,11 @@ static int kvm_sbi_ext_rfence_handler(struct kvm_vcpu *vcpu, struct kvm_run *run
 	case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID:
 	case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA:
 	case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID:
-	/* TODO: implement for nested hypervisor case */
+		/*
+		 * Until nested virtualization is implemented, the
+		 * SBI HFENCE calls should be treated as NOPs
+		 */
+		break;
 	default:
 		ret = -EOPNOTSUPP;
 	}